When Nine Line Apparel launched as an ecommerce store back in 2012, they had no idea how quickly they'd grow. But grow they did: With a three-year growth rate of almost 7,000 percent and more than $14 million in sales by 2016, it's been a steep upward trajectory for this company--and this success landed them at number 31 on the Inc. 5000.

So what's the secret?

For one thing, Tyler Merritt, the store's founder, built this company with an interesting mission in mind. As an active member of the military, his apparel brand promotes a patriotic sensibility--and donates a portion of its revenue to military charities and disaster relief initiatives.

Aside from its mission, Merritt explained that there have been three main facets that have revolutionized the way the company operates: Their inventory management tool, their shipping solution, and their platform for online retail. While the brand started small, these three resources have helped them quickly scale up without losing customers.

1. An inventory management tool. Effective SKU management was one of the first concerns Merritt encountered as the company started to grow. Each time new products were added, it made inventory management more complex. And working in the apparel niche where sizes and returns only make things more complicated, he quickly realized they needed a better tool for inventory management. Once they found a solution (they use SkuVault) that worked with their constantly-growing product base, many of those original problems became more manageable.

2. A shipping solution. Logistically, Nine Line Apparel's quick growth could have been a nightmare. However, by implementing a shipping tool (ShipStation) that allowed them to outsource order fulfillment, shipping became one less aspect of the business to worry about. No matter where Merritt was deployed or working from, he was able to rest assured that order fulfillment was in capable hands.

3. A flexible platform for online retail. Originally, Merritt built his own online selling platform when the company was started back in 2012. However, as the company quickly grew, he found that he needed a platform with more flexibility. His self-built platform couldn't handle the high volume of traffic they were getting, and rapid growth in sales meant increasing complexity. It was time to find another resource.

After weighting several different options for ecommerce platforms, he ultimately picked BigCommerce. Today, Nine Line Apparel works with freelancers and in-house developers to create custom integrations for the store that simplify processes across their various tools and software.

It' hasn't all been easy, though. As a bootstrapped operation, cash and space for inventory have been points of struggle that Merritt has had to deal with on an ongoing basis. At one point, Merritt faced potentially being shut down for operating his business out of his home and violating zoning regulations.

That's not all: As active duty military, Merritt has been deployed amidst this rapid growth--and his wife has had to take the reigns and lead the company while he's away. However, with the staff they've hired (many of which are veterans themselves) and a customer-centric approach, they've been able to manage the operation without having to slow down.

"We work with an extremely talented team that includes many veterans and active duty military--but that's great for us, because they have this mentality of not failing. They take excellent care of our customers," Merritt said.

That approach is working: Thanks to these three resources, a strong team, and a willingness to tackle new challenges, Nine Line Apparel has grown from a home-based online operation to a 60,000 square foot warehouse with a projected 2017 revenue of more than $20 million. "Finding the right tools is a huge part of being able to grow an online business," Merritt said.